12/7/2015 9:00 AM PST BY TMZ STAFF

EXCLUSIVE

Steve Sarkisian has sued USC -- claiming they did him dirty by firing him as the head coach of the football team instead of getting him help for his alcoholism -- and he wants more than $30 MILLION ... TMZ Sports has learned.

TMZ Sports has obtained the suit ... in which Sarkisian reveals he came to grips with the fact he suffered from alcoholism in October 2015 ... after a widely reported meltdown on campus.

Yet, according to the suit ... SC "kicked him to the curb" when he needed its help the most.

We spoke with Sark's attorney, Alan Loewinsohn, who tells us, "Alcoholism is a recognized disability under California law. So firing somebody because of that disability is against the law."

Loewinsohn says Sark wants more than $30 mil to make things right.

Sarkisian wasfired on October 12th after having an alcohol-fueled meltdown at a USC football facility on October 11th.

Sark says after the Oct. 11th incident, he pleaded with athletic director Pat Haden for time off to get help ... but Haden fired him instead less than 24 hours later.

Sark says he was told he was fired over email.

Sark also says he has completed a stint in rehab and is now "sober and ready to return to coaching."

He claims USC has refused to pay the remainder of the contract he signed -- at least $12.6 MILLION -- plus, he wants compensation for the mental anguish he suffered as a result of being fired.

Sarkisian also claims USC had specific knowledge of Steve's alcohol issues -- stemming from an incident at the Salute to Troy event back in August when he slurred and cussed onstage after consuming beers and prescription medication.

Sark says Haden made him sign a letter promising to attend counseling sessions and refrain from future embarrassing incidents fueled by booze.

Sark says the letter proves USC knew he was suffering from alcoholism back then -- and had a duty to help him out ... not fire him.

He's suing for breach of contract, breach of implied covenant of good faith, failure to accommodate, discrimination on the basis of disability, retaliation, violation of confidentiality of medical info and more.

In the suit, Sark says he was inspired to get help by other high profile sports figures battling alcoholism -- including CC Sabathia.

Sark also says he was NOT drunk at the campus incident on Oct. 11th -- but admits he was hungover from the night before and had taken medication shortly before the team meeting.